''Phaeotremella'' is a genus of fungi in the family

Phaeotremellaceae The Phaeotremellaceae are a family of fungi in the order Tremellales. The family currently contains two genera. References {{Taxonbar, from=Q27694646 Tremellomycetes Phaeotremellaceae The Phaeotremellaceae are a family of fungi in the ord ...

. All ''Phaeotremella'' species are parasites of other fungi and produce

anamorph In mycology, the terms teleomorph, anamorph, and holomorph apply to portions of the life cycles of fungi in the phyla Ascomycota and Basidiomycota: *Teleomorph: the sexual reproductive stage (morph), typically a fruiting body. *Anamorph: an ase ...

ic yeast states. Basidiocarps (fruit bodies), when produced, are gelatinous and are colloquially classed among the " jelly fungi". Fifteen or so species of ''Phaeotremella'' are currently recognized worldwide.

Taxonomy

History

The genus ''Phaeotremella'' was originally created by British mycologist

Carleton Rea Carleton Rea (7 May 1861 – 26 June 1946) was an English mycologist, botanist, and naturalist. Background and education Carleton Rea was born in Worcester, the son of the City Coroner. He was educated at The King's School and Magdalen Colle ...

to accommodate ''Phaeotremella pseudofoliacea'', a fungus that resembled a ''

Tremella ''Tremella'' is a genus of fungi in the family Tremellaceae. All ''Tremella'' species are parasites of other fungi and most produce anamorphic yeast states. Basidiocarps (fruit bodies), when produced, are gelatinous and are colloquially classed a ...

'' species but had brown rather than white

basidiospores A basidiospore is a reproductive spore produced by Basidiomycete fungi, a grouping that includes mushrooms, shelf fungi, rusts, and smuts. Basidiospores typically each contain one haploid nucleus that is the product of meiosis, and they are pro ...

. Later authors considered this to be a mistaken observation and placed ''Phaeotremella'' in synonymy with ''Tremella'' and its type species in synonymy with ''Tremella foliacea''.

Molecular A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...

research, based on cladistic analysis of DNA sequences, has however shown that ''Tremella'' is

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

(and hence artificial). A different generic name was therefore required for a group of species not closely related to '' Tremella mesenterica'' (the type species of ''Tremella'') and ''Phaeotremella'' was selected as the earliest such name available. As a result, the current definition of ''Phaeotremella'' is not the same as Rea's original concept. The type species, ''P. pseudofoliacea'', has been placed in synonymy with ''

Phaeotremella frondosa ''Phaeotremella frondosa'' (synonym ''Tremella frondosa'') is a species of fungus in the family Phaeotremellaceae producing brownish, frondose, gelatinous basidiocarps (fruit bodies). It is widespread in north temperate regions, and is para ...

''.

Description

Fruit bodies (when present) are gelatinous. In some species they are small (under 5 mm across) and pustular to pulvinate (cushion-shaped). In others they are much larger (up to 150 mm across) and may be variously lobed or foliose (with leaf-like or seaweed-like fronds). Several ''Phaeotremella'' species are, however, only known from their yeast states.

Microscopic characters

''Phaeotremella'' species produce

hyphae A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

that are typically (but not always) clamped and have haustorial cells from which hyphal filaments seek out and penetrate the hyphae of the host. The basidia are "tremelloid" (globose to ellipsoid and vertically or diagonally septate), giving rise to long, sinuous sterigmata or epibasidia on which the

are produced. These spores are smooth, globose to ellipsoid, and germinate by hyphal tube or by yeast cells. Conidiophores are often present, producing

conidiospores A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to th ...

that are similar to yeast cells.

Habitat and distribution

Species are parasitic on members of the corticioid fungi, specifically species of ''

Aleurodiscus ''Aleurodiscus'' is a genus of corticioid fungi in the family Stereaceae. Species *''Aleurodiscus aberrans, A. aberrans'' *''Aleurodiscus abietis, A. abietis'' *''Aleurodiscus amorphus, A. amorphus'' *''Aleurodiscus atlanticus, A. atlanticus'' * ...

'' and '' Stereum''. Those on ''Aleurodiscus'', including ''Phaeotremella mycophaga'', parasitize the fruit bodies of their hosts; those on ''Stereum'', such as ''

Phaeotremella foliacea ''Phaeotremella foliacea'' (synonym ''Tremella foliacea'') is a species of fungus in the family Phaeotremellaceae. It produces brownish, frondose, gelatinous basidiocarps (fruit bodies) and is parasitic on the mycelium of ''Stereum sanguino ...

'', ''P. frondosa'', and ''P. fimbriata'', parasitize the host mycelium within the wood. As a group, ''Phaeotremella'' species occur worldwide, though individual species may have a more restricted distribution.

Species and hosts

Only species producing basidiocarps (fruit bodies) are listed. Not all hosts are known.

References

{{Taxonbar, from=Q27863235 Tremellomycetes